Basic research on anti-tumor effects of Interferon-α on hepatocellular carcinoma

[目的]研究干扰素-α亚型对人肝癌细胞株体外生长的影响；干扰素-α和5-FU的体外生长抑制作用；干扰素-α诱导细胞凋亡的机制；干扰素-α单独或干扰素-α联合5-FU对人肝癌裸鼠移植瘤生长的影响。[结果]1.检测5种重组干扰素-α亚型(α1、α2、α5、α8、α10；浓度：0~1024IU/mL；对13株人肝癌细胞株的生长抑制作用以干扰素-α5亚型最强，其次为α8、α10、α2、α1.2。2.同时加入干扰素-α和5-FU对肝癌细胞无协同生长抑制作用。3.天然人干扰素-α可不同程度地诱导Caspase-3、-7、-8、-9的激活和PARP的蛋白降解。此外，在干扰素-α处理的细胞中，细胞色素C和Smac/DIABLO被时间依赖性地从线粒体释放到细胞质中。提示线粒体凋亡诱导途径参与了干扰素-α诱导的细胞凋亡。4.皮下注射干扰素-αCon1(0.01、0.1、1μg/只/天；0.01μg/只/只为临床剂量)连续14天，呈剂量和时间依赖性抑制裸鼠肝癌生长。最后，接受0.01、0.1和1μg/只干扰素-αCon1的小鼠的肿瘤体积分别减少到对照肿瘤体积的60%、25%和0-10%。随着干扰素-αCon1剂量的增加，细胞凋亡数明显增加，血管数明显减少。5.干扰素-α联合5-FU对裸鼠肿瘤有协同作用。[结论]某些类型的干扰素-α在肝癌的防治中具有潜在的临床应用价值。

[Purpose] In this study, we examined that the effects of IFN-α subtypes on the growth of human liver cancer cell lines in vitro ; growth inhibitory effects of IFN-α and 5-Fu in vitro ; mechanisms of apoptosis induction by IFN-α; and the effects of IFN-α alone or IFN-α plus 5-Fu on the growth of human liver cancer cell lines transplanted In nude mice.[Results] 1. When we examined the effects of five kinds of recombinant IFN-α subtypes (α1, α2, α5, α8, α10; concentrations: 0-1024 IU/mL; 24-96 hours) on the growth of 13 human liver cancer cell lines, the strongest anti-proliferative effects was noted In IFN-α5 subtype, and followed by α8, α10, α2, α1. 2. No synergistic growth Inhibitory effects could be recognized when IFN-α and 5-Fu were simultaneously added t o the culture of liver cancer cells. 3. Natural human IFN-α induced activation of caspase-3, -7, -8, and -9, and proteolysis of PARP in IFN-α-induced apoptosis-sensitive cell lines at various degrees. In addition, release of cytochrome C and Smac/Diablo from mitochondria into cytoplasm was identified in IFN-α-treated cells time-dependently. These findings suggest mitochondria apoptosis induction pathway is involved in the IFN-α-induced apoptosis. 4. Subcutaneous IFN-αCon1 injection (0.01, 0.1, 1μg/mouse/day; 0.01 μg/mouse = clinical dosesage) for consecutive 14 days dose-and time-dependently suppressed the HCC tumor growth in nude mice. Finally, the tumor volumes of mice received 0.01, 0.1, and 1 μg/mouse of IFN-αCon1 decreased to about 60%, 25%,and 0-10%, respectively, of control tumor volumes. The number of apoptotic cells significantly Increased and the number of blood vessels significantly decreased with the increase of IFN-αCon1 dose. 5. Synergistic effect of IFN-α plus 5-Fu was identified In nude mouse tumors. [Conclusions] These data Indicate the potential clinical application of certain types of IFN-α in the prevention and treatment of HCC.